''He who has Berlin has Germany,'' Lenin once wrote, ''and he who has Germany has Europe.'' The Soviet Union certainly believed this when Russian troops swept into the capital of the crumbling Third Reich in April 1945. And the Allies soon came to believe it, despite Eisenhower's controversial order not to advance on Berlin, which he delivered to his armies two days before the Soviets started their final drive on the capital.

So the history recounted in these two books about the newly reunited city has significance beyond the deceptively limited time and setting they share. In ''Battleground Berlin: Diaries 1945-1948,'' a sequel to her estimable ''Berlin Underground: 1938-1945,'' Ruth Andreas-Friedrich describes the struggle for Berlin from a native's point of view. In a sober telegraphic style (''All of us are lost in thought. No happy thoughts. Finally Jo breaks the silence.'') she conveys what it was like to emerge from the rubble of Gotterdammerung and then to be visited by successive plagues: rape and pillage by Russian soldiers, the suffering of the refugees displaced from the eastern provinces, the developing East-West ideological strife, the bitter cold winter of 1947-48, hunger, illness, shortages and finally the Soviet blockade of 1948.

Though admirable for their moral honesty, their fierce indignation over what Nazism did to Germany and their prescience in foreseeing the building of the Berlin wall, Mrs. Friedrich's diaries are limited in dimension by their use of the present tense. Too much history has ensued and too much commentary on it. George Clare by contrast brings wit, a sense of history and a deep appreciation of the ridiculous to ''Before the Wall: Berlin Days 1946-1948.'' The son of assimilationist Viennese Jews, Mr. Clare was at war with himself over Germany when he took his job with a branch of British intelligence whose assignment was to license ''de-Nazified'' Germans applying to work in the arts and the media. He had first of all to reconcile his admiration for things German with his hatred of the Nazis for killing his parents, a conflict he first described in his moving ''Last Waltz in Vienna,'' published in 1982. He had then to weigh the differences between innocent Germans and guilty Germans and the Germans in between who became guilty innocently.

To this end, for example, he applied to interview Baldur von Schirach, the former Hitler Youth leader and later gauleiter of Vienna, to learn if it was possible to be enlisted in the Nazi Party without applying for membership, as all too many license candidates claimed had happened to them.

In a sequence both hilarious and grotesque, Mr. Clare describes how he got permission to interview Schirach, who was one of only seven inmates in Berlin's Spandau Prison; how the prison guards somehow managed to bring before Mr. Clare the wrong inmate ('' 'Colonel,' I gasped, 'this isn't Schirach, it's Neurath!' 'Well, I'll be damned,' he exclaimed, looking over. 'Why, so it is!'''); and how Schirach eventually confirmed that yes, after 1943 things had gotten so chaotic that many young men probably were installed in the party without their knowledge.

Mr. Clare writes that when Schirach ''unexpectedly and deferentially, used the English 'sir' to address me - the Jewish vermin he would not even have spat at in Vienna - I felt as if he had emptied a bucket of slime . . . all over me.''

Finally, Mr. Clare had to make his judgments in the falling temperature of East-West relations. He is at his discriminating best in analyzing the case of the conductor Wilhelm Furtwangler, whom the Russians were eager to rehabilitate for their own propagandistic purposes while ''many Americans considered'' him ''a former Nazi stooge.'' Mr. Clare reaches no such dramatic conclusions. His review of Furtwangler's career is a study in moral compassion particularly remarkable for someone with so many reasons to feel vengeful. Meanwhile, he believes, Soviet heavy-handedness backfired. The phrase ''Frau komm!'' that he calls ''Russian foreplay'' was ''the most effective anti-Soviet and anti-Communist slogan ever coined.'' As for Russian pressure on politicians and businessmen: it set off the mass emigration from Berlin to West Germany that eventually produced precisely the economic miracle that helped to bring down the Iron Curtain.

''On the other hand,'' he writes, ''the exodus of artists and intellectuals from Berlin had a painful consequence: provincialization, not just of the cultural life of the capital but of the whole of Germany. . . . Away from Berlin and living, often very well, in a diaspora stretching from Hamburg to Munich, Germany's creative community lost much cohesion and productive friction, and this - together with the disappearance of the Jews and their extraordinarily fruitful symbiosis with German culture - made the country, once in the forefront of artistic and intellectual achievement, slide down to second rank.''

As well as being an acute cultural analyst, Mr. Clare, who recently retired as chief British representative for the Springer publishing empire, is a skilled mimic and storyteller. His memoir is alive with impossibly paradoxical people, from Pvt. Hans Levin of England's Alien Pioneer Corps, a soldier to rival the incompetence of the most inept characters in ''Catch-22,'' to Hans Zielenski of Nord-West-Deutscher-Rundfunk, Germany's biggest radio station, whose skill at lying about his Nazi past is almost heroic in its perversity.

But it is the city of Berlin that remains the hero of Mr. Clare's piquant memoir, Berlin the city of black-market cigarettes and coffee and Trummerfrauen pecking indefatigably away at the rubble. ''In Berlin, still Germany's capital, still its intellectual and artistic center, the links between the German and the Western mind were reforged. . . . The Federal Republic, the best Germany Germans and the world have ever known, was not born in Bonn but in Berlin.'' The story of that city in a brief but historically resonant time is what George Clare manages to tell skillfully.